A conventional X-ray CT (Computed Tomography) apparatus is an apparatus which images inside of an object (e.g. patient) by performing an X-ray scan on the patient and processing the acquired data with a computer. Specifically, an X-ray CT apparatus irradiates a patient with X-rays plural times from different directions along a circular orbit around the patient, and detects X-rays transmitted through the patient with an X-ray detector so as to acquire plural detection data. The acquired detection data are subjected to A/D (Analog to Digital) conversion and then transmitted to a console device.
In addition, an X-ray CT apparatus includes a bed equipped with a table on which an object is placed, and imaging of the object is generally performed in an X-ray CT gantry (X-ray scanner) of the X-ray CT apparatus. Further, the bed moves the table into a tunnel part inside the X-ray CT gantry such that the table is inserted in the longitudinal direction of the table. This movement is also referred to as a slide operation.
Since a table of an X-ray CT apparatus generally has such a structure that only one side of the table is supported, deflection occurs on the table due to weight of a patient thereon in the case of sliding the table during imaging. As a result, displacement and/or inclination is included in the acquired image in some cases. As to this problem, a method of correcting a reconstructed image with software has been studied.
However, in correction of such an image with the use of software, correction for smoothing the displacement is performed, but correction of inclination is not considered. In addition to this point, since correction by using hardware has not been implemented in conventional technology, there is a possibility that a patient is misdiagnosed on the basis of the acquired image subjected only to correction of smoothing displacement using software.